Plant functional diversity influences water and carbon fluxes and their use efficiencies in native and disturbed dryland ecosystems

Abstract

Vegetation is changing rapidly in dryland ecosystems, but critical gaps remain in understanding the long-term fluxes of carbon (C) and water. We used 6 years of data from two adjacent eddy covariance sites in the Sonoran Desert, a species-rich woody C 3 native shrubland and a species-poor C 4 shrubland converted to buffelgrass savanna. Although emphasis has been given to the physical determinants of productivity in dryland ecosystems, we assessed how PFTs changes influenced (1) water and C fluxes and (2) water-use (WUEe) and intrinsic C-use efficiencies (CUEei) in the two sites under the same climatological conditions. We hypothesized that changes in PFTs would alter accessibility, rate and use efficiencies of water and carbon, with poorly known effects on the long-term fluxes and efficiencies. Annual net ecosystem productivity (NEP) in the shrubland was a C-source in drier years and a sink in others. However, longer C uptake, greater WUEe and lower CUEei were the crucial drivers for higher and positive NEP (C sink) in the savanna. Annual and seasonal WUEe and CUEei discrepancies indicated the importance of dominant PFTs after disturbance and ecohydrological feedbacks. As the world becomes drier and vegetation disturbance more common, the role of PFT changes should contribute to gaining a clearer understanding of their role in the C and water fluxes of dryland ecosystems.

Ecohydrological interactions during drought

“…In their contribution, Castellanos et al (2022) explored understanding of long‐term carbon fluxes in dryland ecosystems using 6 years of data from two contrasting sites (species‐rich woody C3 native shrubland vs. species‐poor C4 shrubland converted to buffelgrass savanna) in the Sonoran Desert, USA. Their study quantified how plant functional types affect fluxes of carbon and water as well as water‐use and intrinsic carbon use efficiencies.…”

“…The papers span a range of water‐dependent environments: aquatic (Kupferberg et al, 2022; Sabatino et al, 2022; Saltarelli et al, 2022; White et al, 2022), floodplain (Nguyen et al, 2022), terrestrial (Belmonte et al, 2022; Castellanos et al, 2022; Gao, Wang, Li, et al, 2022; Gao, Wang, Wang, et al, 2022; He et al, 2022; Lindh et al, 2022; Parolari & Paschalis, 2022; Xu et al, 2022), wetland and pool interface (Cartwright et al, 2022; Mattei et al, 2022), and regulated, perennial, and intermittent (Di Sabatino et al, 2022; Kupferberg et al, 2022; Saltarelli et al, 2022; Sarremejane et al, 2022; Wegscheider et al, 2022) systems across both modelled‐, field‐, and lab‐based studies to address process research, cascading effects, and novel methodological approaches in ecohydrological research.…”

Navigating uncertainty: Managing herbivore communities enhances Savanna ecosystem resilience under climate change

“…Vegetation conservation is a crucial aspect of management aimed at preserving important grass and tree species, preventing shrub encroachment and identifying critical tipping points (Irob et al., 2022; Kapuka et al., 2022; Lohmann et al., 2012). That is, maintaining a dense grass cover can protect the soil from hot and dry conditions, reducing soil water losses and increasing plant water availability (Castellanos et al., 2022; Irob et al., 2022). Moreover, the significance of maintaining plant functional diversity for ecosystem functioning has gained increasing recognition in recent years (Hagan et al., 2023; Osborne et al., 2018).…”

Advances in the blue‐green space evaluation index system

“…Ecologically, the synergy between water and green spaces in the ecosystem endows the blue‐green space with a significant cooling effect, namely, the Urban Cold Island (UCI) effect, which can effectively alleviate the Urban Heat Island (UHI) effect (Santamouris et al, 2011). Blue‐green spaces can provide enough habitat for organisms (Zhang et al, 2022), purify the air, and reduce noise and carbon storage (Castellanos et al, 2022), thus greatly promoting biodiversity and ecosystem stability (Maller et al, 2005). Economically, compared to cool materials, urban blue‐green spaces have the advantages of low cost, environmental friendliness and political acceptability (Carvalho et al, 2017; Hamada & Ohta, 2010).…”